Overview
Bleomycin is an antineoplastic antibiotic used primarily in combination chemotherapy regimens for various malignancies. It causes DNA strand breaks through free radical formation, particularly effective against squamous cell carcinomas, lymphomas, and testicular cancers. It has unique pulmonary toxicity as a dose-limiting side effect.
Mechanism of Action
Bleomycin binds to DNA, producing single- and double-strand breaks through oxidation of iron-BLM complex, generating free radicals that damage DNA. It inhibits DNA synthesis and causes cell cycle arrest in G2 phase.
Indications
- Hodgkin's lymphoma
- Non-Hodgkin's lymphoma
- Testicular cancer
- Squamous cell carcinomas (head, neck, cervix, skin)
- Malignant pleural effusions (as a sclerosing agent)
Dosage
Typically 10-20 units/m² IV, IM, or SC weekly or twice weekly. For Hodgkin's lymphoma: 10-20 units/m² IV/IM weekly. Total cumulative dose should not exceed 400 units due to pulmonary toxicity risk.
Contraindications
- Hypersensitivity to bleomycin
- Severe pulmonary disease
- Pregnancy (unless benefit outweighs risk)
Side Effects
- Pulmonary fibrosis (dose-limiting)
- Fever/chills (common)
- Skin changes (hyperpigmentation, rash, ulceration)
- Nausea/vomiting
- Alopecia
- Stomatitis
- Anorexia
- Raynaud's phenomenon
Interactions
- Oxygen therapy may enhance pulmonary toxicity
- Other pulmonary toxic drugs (busulfan, cyclophosphamide)
- Radiation therapy enhances toxicity
- Nephrotoxic drugs may increase toxicity